Automated voice message: "On April 26th, your senator, [senator's name removed for privacy], voted against the 'Iraq Accountability Act'..." The recorded voice then asked if I would like to express my outrage/concern regarding my senator's stance by being connected, at no cost, directly to the senator's Washington, DC office by pressing 1 on my keypad. I pressed 1 and expressed MY opinion -- not necessarily that of the robo-caller. The senator's clerk said that they were inundated with calls, which they strongly suspected were coming from MoveOn.org or another similar organization.
According to SuperPages, 202-658-7595 is a Nextel cellphone located in Washington, DC.